It's the famous multiplayer game "Connect 4" on the calc! It features winner detection, but only if you end the game: press the number you want to put your stone in, and press "ENTER" if somebody has won the game.

IMPORTANT!!!
Instructions: before starting the game for the first time, press "2nd", "Matrix", then go to "EDIT", select [A] and press "ENTER".
then change the size of the matrix to "6 X9".
Also, make sure you don't have any graphs plotted in the par mode.

Enjoy!